Delay line circuits



Maly 8, 1962 H. A. BLEAM DELAY LINE CIRCUITS 5 Sheets-Sheet 1 FiledSept. 13, 1956 22 .2 i( I LOAD l INPUT SIGNAL SOURCE TIME BY ZW/2%;

May 8, 1962 H. A. BLEAM 3,034,062

DELAY LINE CIRCUITS Filed Sept. l5, -1956 3 Sheets-Sheet 2 1N PLJI'T'SIGNAL SOURCE IN VEN TOR.

INPUT SIGNAL Il( UTILIzATIoN l SOURCE MEANS I May 8, 1962 H. A. BLEAM3,034,062

DELAY LINE CIRCUITS Filed Sept. 13,41956 5 Sheets-Sheet 5 INPUT /4lSIGNAL 36( gg 44 SOURCE IIE IIIIIIII/IIIIII/ W UTILIZATION MEANS lUTILIzAI'IoN MEANS l l UTILIzATIoN l MEANS l Fvg. 7 l// T 26 EN IN V ENTOR.

United States Patent() 3,034,062 DELAY LINE CIRCUITS Howard A. Bleam,Chicago, Ill., assgnor to Admiral Corporation, Chicago, Ill., acorporation of Delaware Filed Sept. 13, 1956, Ser. No. 609,636 Claims.(Cl. 328-56) This invention relates, generally, to improvements in delaylines, and more particularly to delay line means constructed so that, inresponse to a single input pulse, both positive and negative outputpulses can be obtained simultaneously from a single output means.

In certain applications of delay lines it is desirable that the delayline be capable of producing simultaneously, and from a single outputmeans, a positive signal or pulse and a negative signal or pulse inresponse to a single unidirectional input pulse. For example, suchstructure is useful in pulse train decoding. More specically, thedecoding of a train of pulses sometimes is accomplished by lirsttranslating the train of pulses from a series-arrangement into aparallel-arrangement by means of a delay line having a plurality ofoutput means with Vthe time delays therebetween corresponding to thetime intervals between pulses. rl`hus each of the pulses in a train ofpulses moving along the delay line simultaneously will move past anoutput means individual thereto. Now suppose it is desired to recognizeonly aV particular combination of pulses and to exclude all othercombinations. Such a function can be accomplished by causing the outputmeans which are positioned to respond to superfluous pulses (should theyexist) to produce output pulses of a polarity opposite that of theoutput pulses produced by said particular combination of pulses. Thegroups of pulses containing pulses of both positive and negativepolarity are rejected by circuit means well known in the prior art.

Other uses for a delay line capable of simultaneously producing positiveand negative pulses in response to an applied pulse occur when it isdesired to supply pulses simultaneously to equipments which requireoppositely poled pulses from a given pulse source.

No prior delay line structures are known which will producesimultaneously in response to a single input pulse, output pulses ofopposite polarity from a single output position.

In the delay line structure applications discussed above, it isdesirable that the delay time be reasonably accurate'and that thisaccuracy be maintained with age and use. use o variable delay lines,which can be adjusted to compensate for changes in operatingcharacteristics. Further, in a more general sense, it is desirable thatdelay line structures be variable so that they can be adjusted toperform different functions.

An object of the present invention is to provide a delay line structurefor producing simultaneously a positive and a negative pulse in responseto a single pulse supplied thereto.

Another object of the invention is to provide a reliable and inexpensivedelay line structure for producing simultaneously positive and negativesignal outputs from a single tap position.

Another aim of the invention is to provide a variable delay line whichwill produce simultaneously, positive and negative pulses from a singletap position, in response to a single input pulse.

- A further object of the invention is the improvement of delay lines,generally.

In accordance with the invention, there is provided in combination witha delay line of the type employing Such accuracy can be so maintainedthrough thek kat least one output winding inductively coupled thereto,

an impedance connected across said output winding and having the centerpoint thereon tapped to a reference potential such as ground potential.provided for supplying input signals to said delay line. First circuitmeans are provided for deriving output signals of a rst polarity fromone end terminal of the output winding and second circuit means areprovidedv for deriving output signals of a second polarity from theother end terminal of the output winding.

In accordance with a feature of the invention, the said iirst circuitmeans can comprise a iirst asymmetrical device and the second circuitmeans can comprise a second asymmetrical device. The asymmetricaldevices are poled so that the anode of one asymmetrical device isconnected to the cathode of the other asymmetrical device through saidimpedance.

In accordance with another feature of the invention, the tap of theimpedance may be positioned at points other than the center thereof,thus providing for 0ppositely poled pulses of different ratios ofmagnitude.

In accordance with a further feature of the invention, there can beseveral output windings on the delay line, each of which may beconstructed and arranged to be' moved along the delay linerto providevariations in the time delays of output signals linduced therein.

These and other features and objects of the invention will be more fullyunderstood from the following detailed description thereof when read inconjunction with the drawings, in which:

FIG. 1 is a schematic sketch of a form of the invention;

FIG. 2 is a combination schematic sketch and perspective view of theform of the invention shown in FIG. l;

FIG. 3 shows a waveform of a representative input pulse supplied to theinput of the delay line;

FIGS. 4 and 5 show waveforms of output pulses produced by the delay linein response to the input pulse of FIG. 3;

FIG. 6 is a sketch of another form of the invention;

FIG. 6a illustrates a modification of the form of the invention shown inFIG. 6; and

FIG. 7 is a sketch of a third form of the invention.

It is to be noted that the present invention can be employed generallyin any type delay line which utilizes an output Winding inductivelycoupled to the delay line. Included in this category are, for example,continuously wound electromagnetic-type delay lines, lumpedconstant-type delay lines, and magnetostrictiVe-type' delay lines.

Referring now to FIG. l, there is shown a form of the inventionemploying a continuously wound electromagnetic delay line. A 'winding orcoil l0 consisting of a large number of closely wound turns is woundupon an elongated insulator 11. Pulses are supplied to one end terminalof the winding 10 from the input signal source 16 and travel along thewinding 10 through the impedance matching resistor 14 to groundpotential. Metal strip I2 is positioned adjacent the winding 10 andfunctions to provide a distributed capacitance along the length of thewinding. The impedance looking into the winding l0 from the signalsource 16 approximates the impedance of a transmission line.

The output winding I8 (also referred to herein as a pickup coil) whichconsists of a number of closely Wound turns inductively coupled to thewinding l0, is positioned around the winding 10 and is arranged so thatit can be moved along the Winding l0 to Vary the time delay produced inthe signals induced therein. The resistor 20' is connected across theend terminals of the pickup coil Patented May 8, 1962 Means are 3,187With ai point thereon such as the center point tapped to groundpotential, thus providing for the production of simultaneous pulses ofopposite polarity at opposite end terminals of the coil i8. This can beseen more clearly from the curves of FIGS. 3, 4, and'S, of which thecurve of FIG. 3 represents the Waveform of a representative inputvsignal supplied to delay line, the curve of- FIG. 4 representsthewaveforrn of the signal appearingat the end terminallvof the winding18, and the v curve of FIG. 5 represents the waveform of the signalappearing atl the end terminal 21V of the winding 18. All

of the curves of FIGS. 3, 4, and 5 employ thersame time scale alongtheir abscissas. The rectiers 22 and 26, it will be observed,are'connected so that therectifier V22 willconduct only negative pulsesand the rectifier 26 will Thus the signals represented by the brokenline portions 29 and 31 of the waveconduct only positive pulses.

forms of FIGS. 4 and 5 will not be conducted through the rectitiersrZZand 276and, consequently, will not be posite polarity.l

Referring now to FIG. .2, there is shown the Vconstruction of a specificform of theinvention shown'schernaticallyin FG. 1. Many ofthe elementsof FIG. 2'have Vcorresponding elements in FIG. 1. These correspondingelements are given similar reference characters (primed in FIG. 2).More-specifically, in FIG. 2 input signal source 16', elongatedinsulating core lf, winding 1G',

characters (unprimed) in FIG. l.

l i, 44. The other end terminal is terminated in impedance matchingresistor 43. VOutput winding 34, which is inductvely coupled to thedelay line 33', may be arranged therearound on a spool (not shown), forexample, to enable the moving of the winding 34 along the delay line 33.Tapped impedance 20"', which is connected across the winding 34,asymmetrical devices 22T and 26, and loads 24" and 28", perform the samefunction as the corresponding elements identified by similar referenceIn operation, signals are supplied to the delay line 33 from the inputsignal source 42. Output signals areinduced in the output Winding 34 toproduce simultaneous output pulses of opposite polarity thereacross inthe same manner as describedfin connection with FIG. l.

if desired, the Winding 34 may he comprised of two windings, such as thewindings 45 and 46 shown in FIG. 6a. The two windings 45 and 46 areconnected in seriesarrangement and are wound around the delay line, oneover the other, in such directions that voltages of opposing polaritiesare induced therein. The junction therebetween can be connected toground potential and, in

' response to an input signal supplied to the delay line,

conductive strip 12', pickup winding 18' having end ter` -minals 19 and21', resistor 20', rectiliers 22 and 26',

vloads 24C and 28', and'resistor 14 have corresponding elements yinFIG. 1. In addition, the structure of FIG. 2 comprises a sheet ofinsulating material 13 which is employedto insulate the conductive strip12' from the Winding 10.. A cylindrically shaped insulating member4tlmay be employed to protect the Winding 10. The pickup winding 18 iswound upon a bracket 15 which tits around the winding 10 Vand'which canbe movedalong the Winding 10. The bracketV 15 has two lips'17V thereonwhich have threaded holes therein. A'threaded member output signals ofopposite polarity willappear at the other ends of theV two windings.Such an arrangement provides improved performance over the case where asingle output winding is employed. Y

This improved performance is due to the fact that in the case of asingle winding, thereV is the possibility of a. small difference in timebetween the occurrence of outputsignals at the'twoy end terminalsthereof, owing to the slight inherent time delay in the output windingitself. If two output windings are employed, wound in the mannerdescribed above',V an inherent time delay in one of the output windingswill be cancelled by an equal inherent time delay in the other. It is tobe noted that the Vmodification shown in FIG.v 6a:A is applicable alsofrom the Vinput signal source 38. A soundwave is therebyY generated inthe rod 39 which is of magnetostrictive ma- One end of the threadedmember 19 is mounted in the Y bracket 39 through an aperture 4G `in sucha manner that Y the threaded member is rotatable but cannot move trans-The bracket 39 is secured to the insulator The elements of the pickupWinding assembly 23 co1- Y respond to Various elements of the assemblywhich includes the output winding 318.` More specically, resistor 32corresponds to resistorV 2Q', asymmetrical devices 33 and 34 correspondto-asymmetrical'fdevices 22' and 26',

terial. This sound wave travels along the rod 39 and is detected by theoutput Winding '40.

The tapped resistor 20,Which is connectedY across the Winding 40,asymmetrical devices 22" and.26 and loads 24 and 28"', perform the samefunction as cor responding elements in the circuit of FIG. 1, which havethe same reference characters (unprimed). Y

YIt is'to be noted Vthat the forms of the invention herein shown anddescribed are but preferred embodiments thereof, .and that various.changes may be made in the circuit arrangement and the constructionthereof without departing from the spirit or scope of the invention.

VI claim: i

1. In combination with an electromagnetic delay line comprising anelongated core of insulating material, rst

andV loads 35 and 36 correspond to loads 24 and 2S.

The lips 37 of the assembly 23 are odset with respect to the lips 17 ofspool-like element 15 so that the threaded Y .adjusting element 38 Willnot interfere with the threaded invention employing a lumpedvconstant-type delay line,

represented generallyv by the reference character 33 and Y Vcomprising aWinding 44. Input signal source 42 supplies input :signals tothe'end'terminal of the winding winding means having a largenumber ofclosely wound turns Wound on said elongated core, a conductive stripinsulated yfrom but positioned along said winding to producea'distributed capacitance along said winding means, and means forvsupplying pulsating signals to said first winding means, secondarywinding means comprising a small number of closely wound turns comparedto the number of turns of said llrst winding means, said secondaryWinding means being positioned aroundsaid first winding means, means formoving said secondary winding along said rst winding means, impedancemeans connected across said secondary winding means and having a `pointthereon tapped to a reference potential, means comprising rst rectifiermeans for deriving a tirst pulsating output signal froma tirst endterminal of said secondary Winding means, Vand means comprising a secondrectifier means for deriving a second pulsating outputl signal from thesecond end terminal of said secondary winding means, the cathode of saidfiirst rectifier means being connected to the anode of said secondrectiiier means through said impedance means.

2. In combination with an electromagnetic delay line comprising a firstWinding means having a large number of closely wound turns, means forproducing a distributed capacitance along said first winding means, andmeans for supplying pulsating signals to said first winding means, aspool-like element constructed to -iit around said first Winding meansand having an axial length small compared to the length of said firstwinding means, secondary winding means wound around said spool-likeelement and comprising a small number of closely Wound turns withrespect to the number of turns of said first winding means, means `formoving said spool-like element with respect to said iirst winding means,impedance means connected across said secondary Winding means and havinga point thereon tapped to a reference potential, means or deriving apulsating first output signal of a first polarity from a first endterminal of said secondary Winding means, and means for deriving asecond pulsating output signal of a second polarity from the second endterminal of said secondary winding means.

means, means kfor moving said'spool-li-ke element with respect to saidrst winding means, impedance means connected across said secondarywinding and having a point thereon tapped to a reference potential,means comprising nrst rectifier means for deriving a iirst pulsatingoutput signal from a rst end terminal of said secondary winding means,and means comprising second rectifier means for deriving a secondpulsating output signal from the second end terminal of said secondarywinding means, the cathode of said first rectifier means being connectedto the anode of said second rectifier means through said impedancemeans.

4. A combination in accordance with claim 3, in which said secondarywinding means comprises a third winding and a fourth winding, saidfourth winding being wound over said third winding such that voltages ofopposing polarities are induced in physically corresponding endterminals of said third winding and said fourth winding in response toan input signal supplied to said first winding means, one set of thephysically corresponding end terminals of said third and fourth windingsbeing connected to a common reference potential, the other set ofphysically corresponding end terminals of said third and fourth windingsbeing connected across said impedance means.

5. In combination with a delay line of the lumped constant type andmeans for supplying pulsating signals to said delay line, at least oneoutput winding inductively coupled to a small portion of said delayline, means for moving said output Winding along said delay,line,impedance means connected across said output winding and having a pointthereon connected to a reference potential, means for deriving pulsatingoutput signals of a nrst polarity with respect to said referencepotential from a rst end terminal of said output winding, and means forderiving pulsating output'signals of a second polarity with respect tosaidreference potential from the second end terminal of said winding.

6. A combination in accordance with claim 5, in which end terminal ofsaid output winding comprises a second asymmetrical device having acathode and an anode, the cathode of said first asymmetrical devicebeing connected to the anode of said second asymmetrical device throughsaid impedance means.

7. A combination in accordance with claim 5, in which said outputWinding comprises a second winding and a third winding, said thirdwinding being wound over said second winding such that voltages ofopposing polarities are induced in physically corresponding endterminals of said second Winding and said third winding, one set of thephysically corresponding end terminals of said second and third windingsbeing connected to a common reference potential, the other set ofphysically corresponding end terminals of said second and third windingsbeing connected across said impedance means.

8. In combination with a delay line of the magneto strictive type, meansfor supplying a pulsating signal to said delay line, at least one outputwinding inductively coupled to a small portion of said delay line, meansfor moving said output winding along said delay line, impedance meansconnected across said output winding and having a point thereonconnected to a reference potential, means for deriving pulsating outputsignals of a tirst polarity with respect to said reference potentialfrom a :first end terminal of said output winding, and means forderiving pulsating output signals of a second polarity with respect tosaid reference potential from the second end terminal of said outputwinding.

9. A'combination in accordancev with claim 8, in which said means forderiving pulsating output signals of a first polarity from a first endterminal of said output winding comprises a first asymmetrical devicehaving a cathode and an anode and in which said means for derivingpulsating output signals of a second polarity from the second endterminal of said output winding Vcomprises a second asymmetrical devicehaving a cathode and an anode, the cathode of said iirst asymmetricaldevice being connected to the anode of said second asymmetrical devicethrough said impedance means.

10. A combination in accordance with claim 8, in which said outputwinding comprises a second winding and a third Winding, said thirdwinding being wound over said second winding such that voltages ofopposing .polarities are induced in physically correspondingendterminals of said second winding and said third Winding, one set ofthe physically'corresponding end terminals of said second and thirdwindings being connected to a common reference potential, the other setof physically corresponding end -terminals of said second and thirdwindings being connected across said impedance means.

References Cited in the tile of this patent UNITED STATES PATENTS1,456,909 Pupin May 29, 1923 2,113,148 Weber Apr. 5, 1938 2,540,560Wheeler Feb. 6, 1951 2,611,025 Jankowski Sept. 16, 1952 2,632,847 ReedMar. 24, 1953 2,679,040 Gloess May 18, 1954 2,854,658 Jones Sept. 30,1958 2,914,672 Powell Nov. 24, 1959- FOREIGN PATENTS 104,213 Sweden Feb.5, 1942 OTHER REFERENCES .Applied Electronics, by T. S. Gray, 2nd Ed.,published by Wiley & Sons, 1954 (Pp. 783-84).

